The nice thing about this as opposed to just using spare batteries is that you could use it to charge up your phone a bit, and then use it to charge up someone else's phone as well. Sort of a "puff, puff, give" relationship. I'd love one of these!
this is exactly what i need. i go to school at 8am and usually don't get home till much after 10pm or so. my battery barely makes it through that day and finding an outlet and staying by it while my phone charges is such a hassel. This would be the perfect thing for me!